Bio-based surfactant
- Also known as
- biobased surfactant
A bio-based surfactant is a surfactant made wholly or partly from renewable raw materials, such as plant oils and sugars, by chemical processing. It differs from a biosurfactant, which is produced directly by microorganisms through fermentation.
What is a bio-based surfactant?
A bio-based surfactant is a surfactant whose molecules are built, in whole or in part, from renewable biological raw materials. Common feedstocks are plant oils, such as coconut, palm kernel or rapeseed oil, which supply fatty chains, and sugars or starches, which supply water-attracting head groups. The molecule itself is made by conventional chemical processing.
Examples
- Alkyl polyglucosides, made from glucose and fatty alcohols, which can be fully bio-based.
- Sugar esters and sorbitan esters.
- Fatty alcohol sulfates made from plant-derived fatty alcohols.
- Methyl ester sulfonates, made from plant oil esters.
Some surfactants are only partly bio-based. A plant-derived fatty alcohol that is ethoxylated with petrochemical ethylene oxide, for example, combines renewable and fossil carbon in one molecule; see ethoxylation.
Bio-based surfactants vs. biosurfactants
| Bio-based surfactant | Biosurfactant | |
|---|---|---|
| Raw materials | Renewable feedstocks | Sugars and oils consumed by microorganisms |
| How the molecule is made | Chemical synthesis | Produced by microorganisms during fermentation |
| Can be partly fossil-derived | Yes | Generally no |
| Examples | Alkyl polyglucosides, sugar esters | Sophorolipids, rhamnolipids |
The terms are often used loosely in marketing, so formulators check how an ingredient is actually made and how much of its carbon is renewable.
How biobased content is measured
The share of a surfactant’s carbon that comes from renewable sources is measured by radiocarbon testing under ASTM D6866, and it is the basis for USDA BioPreferred certification. Biobased content describes origin only; it says nothing about biodegradability or toxicity.
Frequently asked questions
No. A bio-based surfactant is made from renewable feedstocks by chemical synthesis. A biosurfactant is made by a microorganism. Both can be renewable in origin, but only a biosurfactant is a fermentation product.
No. Many contain both renewable and petroleum-derived carbon. The percentage is measured with ASTM D6866.
Sources
- USDA BioPreferred Program, U.S. Department of Agriculture
- ASTM D6866, ASTM International
- Surfactants and Interfacial Phenomena, 4th edition, M. J. Rosen and J. T. Kunjappu, Wiley, 2012